1. Field of the Invention
The present invention relates to an electrical power supply system, and, more particularly, to an electrical power supply system, which detects more than one power source being connected to an electrical receptacle.
2. Description of the Related Art
Electrical wiring codes limit the number of receptacles which can be connected to a power entry unit. It is common for an electrical power source to be routed to an electrical receptacle and power then routed from that electrical receptacle to subsequent electrical receptacles in a daisy-chaining manner. Although the electrical wiring has the electrical receptacles connected in parallel, there is no physical limitation in the wiring to prevent the connection of further electrical receptacles without limit nor is there anything in the daisy-chaining of electrical outlets that precludes the chain of electrical outlets to be connected to more than one power source.
If a chain of electrical outlets are connected to two power sources, which happens to be of the same voltage and phase and the units function, a problem can arise in which maintenance personnel may disconnect a power source only to find out that the receptacles are still electrically energized.
Another problem can arise in which in the sequential connection of receptacles a second power source having a different voltage or phase relationship than the one connected at the other end of the chain of receptacles, thereby causing an immediate electrical issue with two voltage sources competing to supply power, which will most likely result in circuits being disconnected by circuit breakers, but generally only after exhibiting some electrical sparking or discharge. This can result in, at the very least, surprise to the maintenance personnel but also potential damage to the wiring and to the equipment attached thereto.
What is needed in the art is a system that will preclude the application of electrical power to each end of a chain of electrical receptacles.